Presently, the recognized test procedures for the determination of gonoccocal infection rely upon culture methods which are laborious, time-consuming, and in the case of asymptomatic infections present in females, the accuracy of cultural methods may be doubtful (see Pariser et al., Southern Medical Journal. Vol. 63, pages 198-201).
Typical procedures are described in the publication "Criteria and Techniques for the Diagnosis of Gonorrhea" published by the United States Public Health Service at the Venereal Disease branch in Atlanta, Georgia. Typically, in males, the presence of gonococcal infection is determined by obtaining urethral cultures which exhibit oxidase-portions colonies of gram-negative diplococci when cultured on Thayer-Martin medium (J. D. Thayer and J. E. Martin, Jr., in Public Health Rep., 79, pages 49-57). In females, gonococcal infection is diagnosed by cervical cultures on Thayer-Martin medium wherein oxidase-positive colonies of gram-negative diplococci appear. In the above culture tests, all cultures are incubated for 18 hours at 37.degree. C. with CO.sub.2 enrichment. The cultural results are frequently confirmed by sugar fermentation studies.
Other tests employed include complement fixation wherein the hemolysis of erythrocytes is monitored. This test is time consuming, the accuracy of results is questionable, and standardization of reagents is a problem. Indirect immuno fluorescence is also employed to measure the amount of gonococcal antibody in sera. However, this test requires complex and costly apparatus as well as a skilled operator.
Experimental progress was made in 1963 when Kellog et al. (J. Bacteriol., Vol. 85, pages 1274-1279) identified four clonal types of N. gonorrhoeae bacteria and demonstrated a correlation between colonial morphology and virulence with two of the four colonial types. The four types are designated as T.sub.1, T.sub.2, T.sub.3, and T.sub.4, with the clonal type one (i.e., T.sub.1) being identified as the primary virulent strain most likely to reflect the antigenic stimulation responsible for antibody production in humans. It is also known that a particular strain of N. gonorrhea designated as F62 will undergo immunochemical region with antibodies developed in response to a wide variety of other strains of N. gonorrhea. Based on this work, a number of different antigens have been derived from the F62-T.sub.1 strain. Examples of this approach are: Lee et al (Infec. Immun., Vol. 1, pages 207-208); Schmale et al. (J. Bacteriol., Vol. 99, pages 469-471); Reising et al (Appl. Microbiol., Vol. 18, pages 337-339); and Lee at al (Appl. Microbiol., Vol. 21, pages 852-853).
While much effort has been expended to develop suitable gonorrheal antigens, there still exists a need to apply previous work in a practical manner to produce an immunochemical test for gonorrhea. Specifically, a need exits to find a carrier particle which can be sensitized with a gonorrheal antigen so that the immunochemical reaction with gonorrheal antibodies can be followed visually to ascertain the presence of infection.
Schuurs (U.S. Pat. No. 3,551,555) teaches that various types of carrier particles (e.g., synthetic latexes or cholesterol crystals) can be presensitized with an inert protein and subsequently sensitized with various materials such as antigens of bacterial origin. It is also known (Reising, Appl. Microbiol., Vol. 21, pages 852-853) that cholesterol particles can be presensitized with lecithin and sensitized with gonorrheal antigen derived as an aqueous supernatant by disruption of cells of gonorrhea bacteria. However, by the resulting test, a microflocculation assay, in females diagnosed clinically and culturally to have gonorrheal infection, only 76% showed a positive microflocculation assay. In males, the correlation was only about 50%. Therefore, while immunochemical testing using some form of presensitization of carrier particles is known, the results as evidenced by the above assay technique have not been sufficiently sensitive to be used in place of the present culture techniques, or on a mass screening basis.